1. Field
The disclosure relates generally to the electronic arts, and more specifically to apparatuses and techniques for adaptive dynamic range control for sigma-delta modulators and other circuits.
2. Background
Sigma-delta modulators and other similar circuits have existed for many years and have a wide range of applications such as communication systems, audio systems, precision measurement devices, and many others. In audio applications, for example, a sigma-delta modulator is often used to covert an audio signal into a stream of one-bit digital signals. The conversion process is performed by oversampling the audio signal, thus spreading the quantization noise over a larger spectrum. The modulator further modifies the spectral properties of the quantization noise such that it is low in the band of interest (i.e., the audio band), and high elsewhere.
In many audio systems, the digital bit stream is processed, stored, retrieved, or transmitted before being converted back to an audio signal for playback. In these systems, errors can be introduced into the digital bit stream due to processing errors, unreliable storage mediums, or disturbances in the transmission medium. These errors can result in significant audio artifacts.
In many audio systems, there is a further desire to lower the oversampling ratio, in order to save computational power and transmission bandwidth. The quantization noise increases in the band of interest (i.e., the audio band) as the oversampling ratio is decreased.
Accordingly, there is a need in the art for improved sigma-delta modulators and similar devices that address audio quality due to errors in the digital bit stream and power, bandwidth limitations.